The call for the data challenge is available here. In particular, note the required procedure:

The participating team has to notify the data challenge committee who is the leader of the team and which of the two tasks they are going to undertake (possibly both), by sending an e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it.
no later than September 30, 2012.

The team leader will be required to sign and fax the Non-Disclosure Agreement provided in the Appendix of the call.

After receiving the signed agreement, the team will be allowed to download the datasets needed for solving the chosen tasks.

The material to be submitted (detailed in the description of each task) should be sent to This email address is being protected from spambots. You need JavaScript enabled to view it.
by December 14, 2012.

At least one author of each of the submissions to the data challenge must register to the WSDM conference prior to December, 14th. Submissions for which none of the authors will be registered by that date will not be evaluated.

The registered participants will present a poster describing their work in a special poster session during the conference.